Relationship between tree rings of Beech (Fagus orientalis) with some climatic variables in experimental forest of Natural Resources Faculty (Darabcola)

Tree ring are one of the most important data sources for reconstructing past climate variability. In order to understand climate variability، it is necessary to get a spatial and temporal coverage of climate information. In dendroclimatology، ring width has been a variable of choice when assessing the tree ring and climate relationships of trees species. We were assessing a ring-width from a dendroclimatic perspective using beech (Fagus orientalis). The aim of this paper is to use tree ring information of Fagus orientalis to assess its capability as a model for reconstruction of Mazandaran province past climate. Therefore، for this purpose tree ring samplings were performed on three selected growing heights of 400، 500، and 700 meters above sea level at northern aspect of Darabcola forest in Mazandaran province. Increment cores were taken from the diameter of breast height (d. b. h.). The rings’ widths were measured using a binocular microscope. Standardization and comparison of tree ring series for each growing elevation were performed for all sites. Radial growth of all Beech tree species in three sites was positively correlated with climatic variables in this regional. Tree Ring chronology show significantly positive correlation with October and December minimum temperature in previous growing season. Maximum temperature in April has inverse relationship with regional chronology. Monthly total precipitation in March and September in current year had positive effect on Radial growth in three sites. Therefore Beech one of the usable species in dendroclimatology studies، this show may can be chronology of Beech extended more than a century in this regional. Also، may can be possible the reconstruction of meteorological data such as mean، minimum and maximum temperature and monthly total precipitation for this region.